Reconfigurable Transparent Flexible Antenna Using Liquid Metal for Wearable Applications

A reconfigurable flexible antenna with visual unobtrusiveness is investigated. Optically transparent and flexible materials are adopted to work as the substrate and to construct the single-layer slot antenna structure. With liquid metal as the parasitic branches, flexibility is maintained and circular polarizations are achieved. Utilizing the fluidity of liquid metal, three reconfigurable operating states, including left-/right-handed circular polarizations both at 2.45-GHz and 5.8-GHz bands, and linear polarization at 3.5-GHz and 5.8-GHz bands, are realized. Combined with a compact size of 0.38λ 0 × 0.38λ 0 × 0.02λ 0 , the proposed antenna is suitable for wearable devices.